WOID BELOW WATER LEWl\ 



I VOID FULL] 



Wow m mi} 



30- 



WOID 25%FULL\ 



I VOID ElilPTY\ 



30h 



Figure 8. — The variation in neutron moisture measurements between control and sample tanks containing 

 large voids is shown. Measurements were made using coarse sand as the porous medium when the water level 

 was changing with respect to the void. 



